This invention relates to a camera system capable of compressing a photographed image data and then storing the compressed image data in a memory.
To increase the S/N ratio of image data, and reduce the size of camera, it has been required that image data is converted into the form of a digital signal and stored in a semiconductor memory. For example, Japanese Unexamined Patent Publication No. 59-183582 discloses an image storing method in which an output of a image pick-up device is A/D-converted into a digital image signal, and the digital image signal is stored in a semiconductor memory, e.g., SRAM, provided in a memory card detachably attached to a camera body.
However, the market price of semiconductor memories is remarkably high. Also, the semiconductor memories have a small storage capacity and cannot store a sufficient number of image data. To overcome these drawbacks, signal compression has been practiced of compressing image data before storing in a semiconductor memory. However, this signal compression raises another problem that a camera photographer cannot observe the image quality deterioration caused by the signal compression until the stored image is reproduced.
Japanese Unexamined Patent Publication No. 1-165267 discloses an electronic still camera which makes it possible that before storing a photographed image data, the photographer can check whether the photographed image data is suitable for photographer""s purpose. In this electronic still camera, however, the checked image data is a photographed image data itself, and not a compressed image data. Accordingly, in the electronic still camera of Japanese Unexamined Patent Publication No. 1-165267, the photographer cannot observe the image quality deterioration caused by the signal compression.
Also, Japanese Unexamined Patent Publication No. 63-286078 discloses a digital image data storing method which enables the photographer to select one among a compression mode and a non-compression mode to store image data in a memory card with high efficiency.
There are many kinds of memory card having different storage capacities. For example, in a case that one frame of still image has an information content of 200 Kbytes, a 128 Kbyte memory card cannot store even one frame of still image, and also 1 Mbyte memory card cannot store more than five frames. Accordingly, it could be seen that the 128 Kbyte memory card cannot be used unless the image data is compressed before stored.
It is a great inconvenience that the storability of a memory card is determined by the storage capacity of the memory card. As mentioned above, also, there are memory cards having different storage capacities. Accordingly, it could be seen that the storage capacity of a memory card cannot be utilized only by changing from the compression mode to the non-compression mode and vice versa. Also, this will place the photographer in a state that the memory card cannot be relied on.
Accordingly, it is an object of the present invention to provide a camera which has overcome the above-mentioned drawbacks.
It is another object of the present invention to provide a camera which makes it possible that the photographer can observe a compressed image data before storing.
It is still another object of the present invention to provide a camera which makes it possible to set a proper compression ratio in accordance with the storage capacity of a memory card and photographer""s purpose.
According to the present invention, a camera comprises image sensing means for sensing an image of an object to be photographed and producing an image data, first storing means for storing information concerning compression, setting means for setting a compression ratio based on the information stored in said first storing means, compression means for compressing the image data at the set compression ratio, and second storing means for storing the compressed image data.
Also, according to the present invention, an image storing medium comprises first storing means for storing data representative of an image, and second storing means for storing information which is used for compressing the data to be stored in said first storing means.
Further, according to the present invention, a camera system comprises a camera main body, image sensing means provided in said camera main body for sensing an image of an object to be photographed and producing an image data, a storing medium detachably attached to the camera main body and including first storing means for storing information concerning compression and second storing means for storing compressed image data, readout means for reading out the information stored in said first storing means, setting means for setting a compression ratio based on the information read out by said readout means, and compression means for compressing the image data at the set compression ratio.
Furthermore, according to the present invention, a photographing apparatus comprises image sensing means for sensing an image of an object to be photographed and producing an image data, processing means for processing the image data, first storing means for storing the image data processed by said processing means, second storing means for storing information concerning processing to be accomplished by said processing means, readout means for reading out the information stored in said second storing means, and controller means for controlling said processing means so as to process the image data in accordance with the information read out by said readout means, and controlling said first storing means so as to store the processed image data.
Moreover, according to the present invention, a camera comprises image sensing means for sensing an image of an object to be photographed and producing an image data, compression means for compressing the image data, setting means for setting a compression ratio for said compression means, displaying means for displaying an image representative of the compressed image data, and storing means for storing the compressed image data.
These and other objects, features and advantages of the present invention will become more apparent upon a reading of the following detailed description and drawings.